1. Field of the Invention
This invention relates to the control of disease in animals, especially poultry, through the use of novel bacteriocin-producing Paenibacillus and Bacillus species and/or novel bacteriocins produced by these species. It also relates to novel bacteriocins, amino acid sequences of the novel bacteriocins, and to the strains of Paenibacillus or Bacillus producing the novel bacteriocins. Furthermore, the invention relates to therapeutic compositions containing the novel bacteriocins and/or the strains of Paenibacillus or Bacillus producing them and to uses of the therapeutic compositions.
2. Description of the Related Art
The consumption of improperly prepared poultry products has resulted in human intestinal diseases. It has long been recognized that Salmonella spp. are causative agents of such diseases and more recently, Campylobacter spp., especially Campylobacter jeuni, has also been implicated. Both microorganisms may colonize poultry gastrointestinal tracts without any deleterious effects on the birds, and although some colonized birds can be detected, asymptomatic carriers can freely spread the microorganisms during production and processing, resulting in further contamination of both live birds and carcasses. Poultry serves as the primary reservoir for Salmonella and Campylobacter in the food supply (Jones et al., Journal of Food Protection, Volume 54, No. 7, 502-507, July, 1991). Prevention of colonization in live poultry during growout production may diminish the problem of poultry contamination.
A number of factors contribute to the colonization and continued presence of bacteria within the digestive tract of animals. These factors have been extensively reviewed by Savage (Progress in Food and Nutrition Science, Volume 7, 65-74, 1983). Included among these factors are: (1) Gastric acidity (Gilliland, Journal of Food Production, Volume 42, 164-167, 1979); (2) bile salts (Sharpe & Mattick, Milchwissenschaft, Volume 12, 348-349, 1967; Floch et al., American Journal of Clinical Nutrition, Volume 25, 1418-1426, 1972; Lewis & Gorbach, Archives of Internal Medicine, Volume 130, 545-549, 1972; Gilliland and Speck, Journal of Food Protection, Volume 40, 820-823, 1977); Hugdahl et al., Infection and Immunity, Volume 56, 1560-1566, 1988); (3) peristalsis; (4) digestive enzymes (Marmur, Journal of Molecular Biology, Volume 3, 208-218, 1961); (5) immune response; and (6) indigenous microorganisms and the antibacterial compounds which they produce. The first four factors are dependent on the phenotype of the host and may not be practically controllable variables. The immune response in the gastrointestinal (GI) tract is not easily modulated. The factors involving indigenous microorganisms and their metabolites are dependent on the normal flora of the GI tract.
One potential approach to control Campylobacter and/or Salmonella colonization is through the use of competitive exclusion (CE). Nurmi and Rantala (Nature, Volume 241, 210-211, 1973) demonstrated effective control of Salmonella infection by gavaging bacteria from healthy poultry intestinal materials into young chicks whose microflora had not yet been established, against Salmonella colonization. Administration of undefined CE preparations to chicks speeds the maturation of gut flora in newly-hatched birds and provides a substitute for the natural process of transmission of microflora from the adult hen to its offspring. Results from laboratory and field investigations provide evidence of benefits in Campylobacter control through administering normal microflora to chickens; decreased frequency of Campylobacter-infected flocks (Mulder and Bolder, IN: Colonization Control of human bacterial enteropathogens in poultry; L. C. Blankenship (ed.), Academic Press, San Diego, Calif., 359-363, 1991) and reduced levels of Campylobacter jejuni (C. jejuni) in the feces of colonized birds has been reported (Stern, Poultry Science, Volume 73, 402-407, 1994).
Schoeni and Wong (Appl. Environ. Microbiol., Volume 60, 1191-1197, 1994) reported a significant reduction in broiler colonization by C. jejuni through the application of carbohydrate supplements together with three identified antagonists: Citrobacter diversus 22, Klebsiella pneumoniae 23, and Escherichia coli 25. There is also evidence of a significant decrease of C. jejuni in intestinal samples from infected broilers after treatment with poultry-isolated cultures of Lactobacillus acidophilus and Streptococcus faecium (Morishita et al., Avian Diseases, Volume 41, 850-855, 1997).
Snoeyenbos et al. (U.S. Pat. No. 4,335,107, June, 1982) developed a competitive exclusion (CE) microflora technique for preventing Salmonella colonization by lyophilizing fecal droppings and culturing this preparation anaerobically. Mikola et al. (U.S. Pat. No. 4,657,762, April, 1987) used intestinal fecal and cecal contents as a source of CE microflora for preventing Salmonella colonization. Stern et al. (U.S. Pat. No. 5,451,400, September, 1995 and U.S. Pat. No. 6,241,335, April 2001) disclose a mucosal CE composition for protection of poultry and livestock against colonizations by Salmonella and Campylobacter where the mucin layer of prewashed caeca is scraped and the scrapings, kept in an oxygen-free environment, are cultured anaerobically. Nisbet et al. (U.S. Pat. No. 5,478,557, December, 1996) disclose a defined probiotic that can be obtained from a variety of domestic animals which is obtained by continuous culture of a batch culture produced directly from fecal droppings, cecal and/or large intestine contents of the adult target animal.
Microorganisms produce a variety of compounds which demonstrate anti-bacterial properties. One group of these compounds, the bacteriocins, consists of bactericidal proteins with a mechanism of action similar to ionophore antibiotics. Bacteriocins are often active against species which are closely related to the producer. Their widespread occurrence in bacterial species isolated from complex microbial communities such as the intestinal tract, the oral or other epithelial surfaces, suggests that bacteriocins may have a regulatory role in terms of population dynamics within bacterial ecosystems. Bacteriocins are defined as compounds produced by bacteria that have a biologically active protein moiety and bactericidal action (Tagg et al., Bacteriological Reviews, Volume 40, 722-256, 1976). Other characteristics may include: (1) a narrow inhibitory spectrum of activity centered about closely related species; (2) attachment to specific cell receptors; and (3) plasmid-borne genetic determinants of bacteriocin production and of host cell bacteriocin immunity. Incompletely defined antagonistic substances have been termed “bacteriocin-like substances”. Some bacteriocins effective against Gram-positive bacteria, in contrast to Gram-negative bacteria, have wider spectrum of activity. It has been suggested that the term bacteriocin, when used to describe inhibitory agents produced by Gram-positive bacteria, should meet the minimum criteria of (1) being a peptide and (2) possessing bactericidal activity (Tagg et al., supra).
Diverse biological activities are common among Bacillus spp. This genus can produce pronounced antagonism to pathogenic microorganisms. To create this antagonism, bacilli may manifest amylolytic, cellulolytic, lipolytic, proteolytic, and pectinolytic activities. They can generate lysozyme and are effectively involved in synthesis of numerous amino acids and other biologically active substances (Zani et al., Journal of Applied Microbiology, Volume 84, 68-71, 1988; Sorokulova et al., Anitbiotiki i Khemioterpaiya, Volume 41 (10), 13-15, 1992). Except for Bacillus anthracis and B. cereus, members of the genus Bacillus are harmless for warm-blooded host animals and have phylogenetic relatedness to lactobacilli (Fox, Science, Volume 209, No. 4455, page 457, 1980). Owing to these desirable characteristics, bacteria within the genus Bacillus spp. have found wide application as probiotics and are widely used in medicine and veterinary practice (Smirnov et al, Microbiol. J., Volume 54(6), 82-93, 1992).
Raczek (United States Patent Application U.S. 2002/0176910, published Nov. 28, 2002) discloses the use of a composition that contains live or dead microorganisms which secrete bacteriocins, or the bacteriocins themselves or in combinations thereof, for use with feedstuffs for agricultural livestock.
Puiri et al. (Letters in Applied Microbiology, Volume 27, 9-13, 1998) disclose a novel antimicrobial compound secreted by a Paenibacillus polymyxa strain isolated from fermented sausages. The bacteriocin-like properties included a proteinaceous nature (sensitive to proteases), insensitivity to organic solvents and chelators, stability to heat (up to 10 minutes at 90° C.), and acidic pH but instability in alkaline conditions. The bacteriocin-like compound has a molecular mass of 10 kDa. It showed inhibitory activity to several species of Bacillus, Paenibacillus, Lactobacillus, Micrococcus luteus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Serratia marcescens. It showed no inhibitory activity to Staphylococcus aureus, Pseudomonas aeruginosa, or Salmonella newport. 
The present invention provides novel compositions containing a novel strain of a Paenibacillus or Bacillus species and/or novel bacteriocins produced by the novel strains; a method of using the strain or bacteriocin, the novel strains, amino acid sequences for the novel bacteriocins, and methods of use, all of which are different from related art strains, bacteriocins, and methods of using.